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      1 //===- BugDriver.h - Top-Level BugPoint class -------------------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This class contains all of the shared state and information that is used by
     11 // the BugPoint tool to track down errors in optimizations.  This class is the
     12 // main driver class that invokes all sub-functionality.
     13 //
     14 //===----------------------------------------------------------------------===//
     15 
     16 #ifndef LLVM_TOOLS_BUGPOINT_BUGDRIVER_H
     17 #define LLVM_TOOLS_BUGPOINT_BUGDRIVER_H
     18 
     19 #include "llvm/IR/ValueMap.h"
     20 #include "llvm/Transforms/Utils/ValueMapper.h"
     21 #include <memory>
     22 #include <string>
     23 #include <vector>
     24 
     25 namespace llvm {
     26 
     27 class Value;
     28 class PassInfo;
     29 class Module;
     30 class GlobalVariable;
     31 class Function;
     32 class BasicBlock;
     33 class AbstractInterpreter;
     34 class Instruction;
     35 class LLVMContext;
     36 
     37 class DebugCrashes;
     38 
     39 class CC;
     40 
     41 extern bool DisableSimplifyCFG;
     42 
     43 /// BugpointIsInterrupted - Set to true when the user presses ctrl-c.
     44 ///
     45 extern bool BugpointIsInterrupted;
     46 
     47 class BugDriver {
     48   LLVMContext& Context;
     49   const char *ToolName;            // argv[0] of bugpoint
     50   std::string ReferenceOutputFile; // Name of `good' output file
     51   Module *Program;             // The raw program, linked together
     52   std::vector<std::string> PassesToRun;
     53   AbstractInterpreter *Interpreter;   // How to run the program
     54   AbstractInterpreter *SafeInterpreter;  // To generate reference output, etc.
     55   CC *cc;
     56   bool run_find_bugs;
     57   unsigned Timeout;
     58   unsigned MemoryLimit;
     59   bool UseValgrind;
     60 
     61   // FIXME: sort out public/private distinctions...
     62   friend class ReducePassList;
     63   friend class ReduceMisCodegenFunctions;
     64 
     65 public:
     66   BugDriver(const char *toolname, bool find_bugs,
     67             unsigned timeout, unsigned memlimit, bool use_valgrind,
     68             LLVMContext& ctxt);
     69   ~BugDriver();
     70 
     71   const char *getToolName() const { return ToolName; }
     72 
     73   LLVMContext& getContext() const { return Context; }
     74 
     75   // Set up methods... these methods are used to copy information about the
     76   // command line arguments into instance variables of BugDriver.
     77   //
     78   bool addSources(const std::vector<std::string> &FileNames);
     79   void addPass(std::string p) { PassesToRun.push_back(p); }
     80   void setPassesToRun(const std::vector<std::string> &PTR) {
     81     PassesToRun = PTR;
     82   }
     83   const std::vector<std::string> &getPassesToRun() const {
     84     return PassesToRun;
     85   }
     86 
     87   /// run - The top level method that is invoked after all of the instance
     88   /// variables are set up from command line arguments. The \p as_child argument
     89   /// indicates whether the driver is to run in parent mode or child mode.
     90   ///
     91   bool run(std::string &ErrMsg);
     92 
     93   /// debugOptimizerCrash - This method is called when some optimizer pass
     94   /// crashes on input.  It attempts to prune down the testcase to something
     95   /// reasonable, and figure out exactly which pass is crashing.
     96   ///
     97   bool debugOptimizerCrash(const std::string &ID = "passes");
     98 
     99   /// debugCodeGeneratorCrash - This method is called when the code generator
    100   /// crashes on an input.  It attempts to reduce the input as much as possible
    101   /// while still causing the code generator to crash.
    102   bool debugCodeGeneratorCrash(std::string &Error);
    103 
    104   /// debugMiscompilation - This method is used when the passes selected are not
    105   /// crashing, but the generated output is semantically different from the
    106   /// input.
    107   void debugMiscompilation(std::string *Error);
    108 
    109   /// debugPassMiscompilation - This method is called when the specified pass
    110   /// miscompiles Program as input.  It tries to reduce the testcase to
    111   /// something that smaller that still miscompiles the program.
    112   /// ReferenceOutput contains the filename of the file containing the output we
    113   /// are to match.
    114   ///
    115   bool debugPassMiscompilation(const PassInfo *ThePass,
    116                                const std::string &ReferenceOutput);
    117 
    118   /// compileSharedObject - This method creates a SharedObject from a given
    119   /// BitcodeFile for debugging a code generator.
    120   ///
    121   std::string compileSharedObject(const std::string &BitcodeFile,
    122                                   std::string &Error);
    123 
    124   /// debugCodeGenerator - This method narrows down a module to a function or
    125   /// set of functions, using the CBE as a ``safe'' code generator for other
    126   /// functions that are not under consideration.
    127   bool debugCodeGenerator(std::string *Error);
    128 
    129   /// isExecutingJIT - Returns true if bugpoint is currently testing the JIT
    130   ///
    131   bool isExecutingJIT();
    132 
    133   /// runPasses - Run all of the passes in the "PassesToRun" list, discard the
    134   /// output, and return true if any of the passes crashed.
    135   bool runPasses(Module *M) const {
    136     return runPasses(M, PassesToRun);
    137   }
    138 
    139   Module *getProgram() const { return Program; }
    140 
    141   /// swapProgramIn - Set the current module to the specified module, returning
    142   /// the old one.
    143   Module *swapProgramIn(Module *M) {
    144     Module *OldProgram = Program;
    145     Program = M;
    146     return OldProgram;
    147   }
    148 
    149   AbstractInterpreter *switchToSafeInterpreter() {
    150     AbstractInterpreter *Old = Interpreter;
    151     Interpreter = (AbstractInterpreter*)SafeInterpreter;
    152     return Old;
    153   }
    154 
    155   void switchToInterpreter(AbstractInterpreter *AI) {
    156     Interpreter = AI;
    157   }
    158 
    159   /// setNewProgram - If we reduce or update the program somehow, call this
    160   /// method to update bugdriver with it.  This deletes the old module and sets
    161   /// the specified one as the current program.
    162   void setNewProgram(Module *M);
    163 
    164   /// compileProgram - Try to compile the specified module, returning false and
    165   /// setting Error if an error occurs.  This is used for code generation
    166   /// crash testing.
    167   ///
    168   void compileProgram(Module *M, std::string *Error) const;
    169 
    170   /// executeProgram - This method runs "Program", capturing the output of the
    171   /// program to a file.  A recommended filename may be optionally specified.
    172   ///
    173   std::string executeProgram(const Module *Program,
    174                              std::string OutputFilename,
    175                              std::string Bitcode,
    176                              const std::string &SharedObjects,
    177                              AbstractInterpreter *AI,
    178                              std::string *Error) const;
    179 
    180   /// executeProgramSafely - Used to create reference output with the "safe"
    181   /// backend, if reference output is not provided.  If there is a problem with
    182   /// the code generator (e.g., llc crashes), this will return false and set
    183   /// Error.
    184   ///
    185   std::string executeProgramSafely(const Module *Program,
    186                                    std::string OutputFile,
    187                                    std::string *Error) const;
    188 
    189   /// createReferenceFile - calls compileProgram and then records the output
    190   /// into ReferenceOutputFile. Returns true if reference file created, false
    191   /// otherwise. Note: initializeExecutionEnvironment should be called BEFORE
    192   /// this function.
    193   ///
    194   bool createReferenceFile(Module *M, const std::string &Filename
    195                                             = "bugpoint.reference.out-%%%%%%%");
    196 
    197   /// diffProgram - This method executes the specified module and diffs the
    198   /// output against the file specified by ReferenceOutputFile.  If the output
    199   /// is different, 1 is returned.  If there is a problem with the code
    200   /// generator (e.g., llc crashes), this will return -1 and set Error.
    201   ///
    202   bool diffProgram(const Module *Program,
    203                    const std::string &BitcodeFile = "",
    204                    const std::string &SharedObj = "",
    205                    bool RemoveBitcode = false,
    206                    std::string *Error = nullptr) const;
    207 
    208   /// EmitProgressBitcode - This function is used to output M to a file named
    209   /// "bugpoint-ID.bc".
    210   ///
    211   void EmitProgressBitcode(const Module *M, const std::string &ID,
    212                            bool NoFlyer = false) const;
    213 
    214   /// This method clones the current Program and deletes the specified
    215   /// instruction from the cloned module.  It then runs a series of cleanup
    216   /// passes (ADCE and SimplifyCFG) to eliminate any code which depends on the
    217   /// value. The modified module is then returned.
    218   ///
    219   std::unique_ptr<Module> deleteInstructionFromProgram(const Instruction *I,
    220                                                        unsigned Simp);
    221 
    222   /// This method clones the current Program and performs a series of cleanups
    223   /// intended to get rid of extra cruft on the module. If the
    224   /// MayModifySemantics argument is true, then the cleanups is allowed to
    225   /// modify how the code behaves.
    226   ///
    227   std::unique_ptr<Module> performFinalCleanups(Module *M,
    228                                                bool MayModifySemantics = false);
    229 
    230   /// Given a module, extract up to one loop from it into a new function. This
    231   /// returns null if there are no extractable loops in the program or if the
    232   /// loop extractor crashes.
    233   std::unique_ptr<Module> extractLoop(Module *M);
    234 
    235   /// Extract all but the specified basic blocks into their own functions. The
    236   /// only detail is that M is actually a module cloned from the one the BBs are
    237   /// in, so some mapping needs to be performed. If this operation fails for
    238   /// some reason (ie the implementation is buggy), this function should return
    239   /// null, otherwise it returns a new Module.
    240   std::unique_ptr<Module>
    241   extractMappedBlocksFromModule(const std::vector<BasicBlock *> &BBs,
    242                                 Module *M);
    243 
    244   /// Carefully run the specified set of pass on the specified/ module,
    245   /// returning the transformed module on success, or a null pointer on failure.
    246   /// If AutoDebugCrashes is set to true, then bugpoint will automatically
    247   /// attempt to track down a crashing pass if one exists, and this method will
    248   /// never return null.
    249   std::unique_ptr<Module> runPassesOn(Module *M,
    250                                       const std::vector<std::string> &Passes,
    251                                       bool AutoDebugCrashes = false,
    252                                       unsigned NumExtraArgs = 0,
    253                                       const char *const *ExtraArgs = nullptr);
    254 
    255   /// runPasses - Run the specified passes on Program, outputting a bitcode
    256   /// file and writting the filename into OutputFile if successful.  If the
    257   /// optimizations fail for some reason (optimizer crashes), return true,
    258   /// otherwise return false.  If DeleteOutput is set to true, the bitcode is
    259   /// deleted on success, and the filename string is undefined.  This prints to
    260   /// outs() a single line message indicating whether compilation was successful
    261   /// or failed, unless Quiet is set.  ExtraArgs specifies additional arguments
    262   /// to pass to the child bugpoint instance.
    263   ///
    264   bool runPasses(Module *Program,
    265                  const std::vector<std::string> &PassesToRun,
    266                  std::string &OutputFilename, bool DeleteOutput = false,
    267                  bool Quiet = false, unsigned NumExtraArgs = 0,
    268                  const char * const *ExtraArgs = nullptr) const;
    269 
    270   /// runManyPasses - Take the specified pass list and create different
    271   /// combinations of passes to compile the program with. Compile the program with
    272   /// each set and mark test to see if it compiled correctly. If the passes
    273   /// compiled correctly output nothing and rearrange the passes into a new order.
    274   /// If the passes did not compile correctly, output the command required to
    275   /// recreate the failure. This returns true if a compiler error is found.
    276   ///
    277   bool runManyPasses(const std::vector<std::string> &AllPasses,
    278                      std::string &ErrMsg);
    279 
    280   /// writeProgramToFile - This writes the current "Program" to the named
    281   /// bitcode file.  If an error occurs, true is returned.
    282   ///
    283   bool writeProgramToFile(const std::string &Filename, const Module *M) const;
    284   bool writeProgramToFile(const std::string &Filename, int FD,
    285                           const Module *M) const;
    286 
    287 private:
    288   /// runPasses - Just like the method above, but this just returns true or
    289   /// false indicating whether or not the optimizer crashed on the specified
    290   /// input (true = crashed).
    291   ///
    292   bool runPasses(Module *M,
    293                  const std::vector<std::string> &PassesToRun,
    294                  bool DeleteOutput = true) const {
    295     std::string Filename;
    296     return runPasses(M, PassesToRun, Filename, DeleteOutput);
    297   }
    298 
    299   /// initializeExecutionEnvironment - This method is used to set up the
    300   /// environment for executing LLVM programs.
    301   ///
    302   bool initializeExecutionEnvironment();
    303 };
    304 
    305 ///  Given a bitcode or assembly input filename, parse and return it, or return
    306 ///  null if not possible.
    307 ///
    308 std::unique_ptr<Module> parseInputFile(StringRef InputFilename,
    309                                        LLVMContext &ctxt);
    310 
    311 /// getPassesString - Turn a list of passes into a string which indicates the
    312 /// command line options that must be passed to add the passes.
    313 ///
    314 std::string getPassesString(const std::vector<std::string> &Passes);
    315 
    316 /// PrintFunctionList - prints out list of problematic functions
    317 ///
    318 void PrintFunctionList(const std::vector<Function*> &Funcs);
    319 
    320 /// PrintGlobalVariableList - prints out list of problematic global variables
    321 ///
    322 void PrintGlobalVariableList(const std::vector<GlobalVariable*> &GVs);
    323 
    324 // DeleteGlobalInitializer - "Remove" the global variable by deleting its
    325 // initializer, making it external.
    326 //
    327 void DeleteGlobalInitializer(GlobalVariable *GV);
    328 
    329 // DeleteFunctionBody - "Remove" the function by deleting all of it's basic
    330 // blocks, making it external.
    331 //
    332 void DeleteFunctionBody(Function *F);
    333 
    334 /// Given a module and a list of functions in the module, split the functions
    335 /// OUT of the specified module, and place them in the new module.
    336 std::unique_ptr<Module>
    337 SplitFunctionsOutOfModule(Module *M, const std::vector<Function *> &F,
    338                           ValueToValueMapTy &VMap);
    339 
    340 } // End llvm namespace
    341 
    342 #endif
    343